We'll see.
I doubt it (that he's lost his speed).
Zeke was a little heavier in his 2nd-season, playing near 230lbs., & he stilled reeled off this play:
... which, in my opinion, is the best of his entire career.
Even 5lbs. heavier than his rookie year, he showed plenty of speed on that play. This season, reports are that Zeke slimmed down into the low 220s, one article even suggesting he'd gotten as low as 221#, and I suspect is currently capable of hitting speeds greater than what we see in the clip above. Time will tell, but I'm unconcerned...
Now, Zeke will never be Chris Johnson. He is not the fastest guy in the league & never will be. But he does have exceptional speed for the halfback position. It's just, he happened to enter the league at a time when multiple other "generational" halfbacks appeared as well. You usually don't find those guys but once every ten-to-fifteen years or so. But currently, we've had Gurley, Zeke, Derrick Henry, Leonard Fournette, and Saquon Barkley in successive years. All those guys have unusual speed for the position, so it makes Zeke seem a little less special. But make no mistake, Elliott is faster than most other backs in the NFL.
I think he'll see some lanes this year that will allow him to really hit the gas. So far in 2019, I've liked his burst, his vision, and his effort. The long-game will come soon enough...
#MIAMI